Purpose : To assess fatty liver by 19F-MRS and 31P-MRS,observing 5-fluorouracil metabolism (anabolize to fluoronucleotide (Fnct) and catabolize to alpha-fluoro-beta-alanine (FBAL)) and fructose metabolism (mainly inverted to fructose-1-phosphate), respectively.Materials and Methods : Male Wistar Slc rats were examined on BEM170/200 (4.7T,Otsuka Electronics) with 17mm-diameter surface coil. Fatty liver was induced by choline deficient diet (CD diet) given for 2 or 4 weeks. 19F-MR spectra were obtained for 100min.after 5-FU intravenous injection. 31P-MR spectra were obtained pre and post fructose injection. 19F-MRS and 31P-MRS studies were performed in separated experiments.Results : In 19F-MRS,high Fnct peak and suppressed FBAL peak was observed in CD diet group. In 31P-MRS,no significant difference could be seen between CD diet group and control diet group about the time course of phosphomonoester (PME) and adenosine-triphosphate (ATP).Conclusion : We detected the high peak of Fnct that may reflect the recovering reaction from liver damage but the difference of fructose metabolism was not evident. In damaged liver, the injured metabolic pathway and severity is different among the diseases and individuals. The dynamic study with in vivo MRS has the possibility to detect the impaired point and the severity. We proposed that it is very important to try some different methods to evaluate liver function and in vivo dynamic MRS may be valuable for it.